etude de la qualite des eaux d'un hydrosysteme fluvial ... - LTHE

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During these campaigns, samples were collected nearby the surface and filtered immediatelyafter the sampling with membrane of 0.45 µm of pore size. In-situ measured parameters aretemperature, DO, pH, alkalinity, hardness, NH + 4 , NO - 2 , NO - 3 , PO 3- 4 , S 2- , SO 2- 4 , Cl 2 , Cl - , Mn 4+ ,Fe tot , Fe 2+ . Beside, samples were also taken to the laboratory for other determinations (Na, K,Fe, Cd, Pb) (Prieur, 2001).There are some advantages of mobile campaigns compared to the experiments carried out inthe laboratory. In mobile samplings, in-situ measurements of unstable parameters were carriedout in portable equipment such as pH meter, DO meter, portable spectrometer-Hach Drell2010. Especially, the measurements of alkalinity, hardness, reducing parameters like NO + 2 ,S 2- , Fe 2+ , Mn 4+ were carried out in situ. These parameters, usually, after transportation andreservation before analysis in laboratory are easily oxidized. In the other hand, this type ofequipment is known to give less accurate results as summarized in table below.2.6. Specific experimentsBeside the experiments devoted to water quality survey, some specific experiments werecarried out order to understand the boundary factors of the studied river.2.6.1. Sediment-water experimentsIt is now well recognized that sediment in shallow water is essential in controlling waterquality. Biological conversions taking place in the sediment are main source for water qualityevolution. A specific experiment of the impact of sediment to water and vice versa thedeposition of material and organisms from water to sediment has been conducted.A Bell Jar unit was set up and employed in situ.30
Figure 1.2.9 presents the photos of a Bell Jar unitutilized in monitoring the water-sediment fluxes. Inspite of its simplicity, the unit performs as robust andeffective tool in online monitoring of water-sedimentinterface (Chesterikoff et al., 1992). Practically, theBell-Jar unit has two simultaneous functions; (1)blocking certain volume of bottom water (close tosediment) from river water mass and (2) samplingwater and measuring water quality of blocked watervolume.Figure 1.2.9: Bell-Jar unit; 1: Multi probesensor; 2 Open end plastic box; 3:Reinforcement frameThe blocked water volume is always in natural contact with bottom sediment and it makes thefluxes of nutrients, organic material, organisms, and etc in their natural paces through watersediment interface. Since the blocked water is finite in volume, the traces of fluxes can berecorded via the change in water quality (the influence of sediment flux is stronger thanvariation of water quality in aqueous phase itself).In their research in Seine river, Chesterikoff et al. (1992) observed an oxygen exhaustion afteronly 2-4 hours in summer while in un-trapped water mass, DO was observed nearlyconstantly over the same time. The water samples were also collected for lab works. A smallvolume of water inside the incubator is extracted via a capillary tube to the water surface by a50 ml syringe. One end of the capillary tube is drilled and patched inside the incubator and theother end is connected with the syringe staying in the water surface.No Name Location Date1 Thuy Phuong (N1) 0 km 12/25/02, 08/17/032 Trung Hoa (N2-N3) About 11 km 01/08/03, 05/03, 08/16/033 Cau Den (N3) 15.2 km 05/03, 07/18/03, 08/01/034 Cau To (confluence) 20.2 km 05/035 Khe Tang (NT1) 25 km 05/03, 07/29/03, 07/30/03, 07/31/036 Cau Chiec (NT2) 33 km 01/15/03, 05/03Table 1.2.11: Locations of benthic experiments31
Page 3: THESISFor obtaining the doctorate d
Page 6: 3. utilisation de ce modèle pour
Page 10 and 11: L’ensemble de ces indices permet
Page 12 and 13: 2. Modélisation du système fluvia
Page 14 and 15: 3. Caractéristiques principales de
Page 17 and 18: ForewordsThis thesis pursues an env
Page 19: Principal contentsIntroduction 1Pre
Page 22: framework for which it was develope
Page 25 and 26: PART 1: PRESENTATION OF THE STUDY5
Page 27 and 28: 1. The Nhue-To Lich river basins1.1
Page 29 and 30: 3.77 m for low and high irrigation,
Page 31 and 32: 1.2.2. RainfallFigure 1.1.4: Monthl
Page 33 and 34: Over the whole year, the monthly av
Page 35 and 36: Figure 1.1.15: Pie chart of land us
Page 37 and 38: 2. Data base constructionIn order t
Page 39 and 40: 2.2. Organization of the field surv
Page 41 and 42: confluence point. The other points
Page 43 and 44: In summary, the frequency of the ex
Page 45 and 46: Point Time Level Discharge Cross-se
Page 47 and 48: conducted independently from the sc
Page 49: Figure 1.2.7: DO in on-boat surveyF
Page 53 and 54: degradable organic fraction in tota
Page 55 and 56: natural products chemistry led by P
Page 57 and 58: The analysis of chlorophyll-a is ca
Page 59 and 60: small comparison between DOC, BOD m
Page 61 and 62: 3. Hydrology of the Nhue-To Lich ri
Page 63 and 64: Figure 1.3.3: Gate structure at the
Page 65 and 66: The rating curve at Cau Den was als
Page 67 and 68: counted here is constantly distribu
Page 69 and 70: 4. Water quality of the Nhue-To-Lic
Page 71 and 72: Figure 1.4.5: DO extracted from mon
Page 73 and 74: the contrary, the low correlation o
Page 75 and 76: Figure 1.4.13: PCA of the upstream
Page 77 and 78: anthropogenic impact is short at th
Page 79 and 80: In conclusion, the seasonal variati
Page 81 and 82: NO3 in nitrification process requir
Page 83 and 84: PART 2: MODELLING OF THE NHUE-TOLIC
Page 85 and 86: IntroductionOne objective of this t
Page 87 and 88: definition of the system identifies
Page 89 and 90: Y = [(Σ((x c - x m ) 2 /x m,a )/n]
Page 91 and 92: 3. The validation criteria are form
Page 93 and 94: 1.2.2. Hydrodynamics and hydraulics
Page 95 and 96: AQUASIM's second task is to perform
Page 97 and 98: QUAL2 was specifically designed to
Page 99 and 100: UK; Wallingford Software 1994); 8 =
Page 101 and 102:
system will be declared in the next
Page 103 and 104:
The performance of parameter estima
Page 105 and 106:
Based on these 3 factors, we have c
Page 107 and 108:
The lengths of the first, the secon
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Figure 2.2.2: Rear Thuy Phuong dam
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2.3.3. Biochemical conceptual schem
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1973; Yen, 1979; French, 1985). The
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+ Heterotrophic growth on dissolved
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The loss of heterotrophic biomass i
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O 2 /l)P/l)S NH4 : concentration of
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In contrast, the Nhue river is ofte
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2.4.2.1.4. Estimation of the kineti
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In fresh water environment, the equ
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+ NH 4 exchangeIn this equation, th
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τ cd : critical shear stress for d
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The critical shear stress for erosi
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2.4.2.2.6. Precipitation/dissolutio
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The table 2.2.9 represents complete
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3.2. Initial and boundary condition
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N1TLSpecies Prior simulation After
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3.3. Simulation prior to calibratio
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adsorption in our river. The decrea
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and an intermediate class 2 with
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3. The half-saturation coefficients
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negligible factor in the polluted a
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3.5. Results of the post-calibratio
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conceptual scheme and in providing
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case of inundation. We suppose that
Page 157 and 158:
the inconsistence data employed in
Page 159 and 160:
4. Simulation of the transient stat
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water discharge can dilute the diss
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this modelling period with previous
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4.4.1.3. Estimation of accumulative
Page 167 and 168:
4.4.2.2. Boundary conditions for un
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Figure 2.4.19: Initial condition of
Page 171 and 172:
The diurnal variation is another tr
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Figure 2.4.29: Simulated and measur
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August 1 st to 4 th 2003. Of which
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The wind speed was predicted from t
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occurrence is regular whenever rain
Page 181 and 182:
Figure 2.4.47: Boundary condition o
Page 183 and 184:
Figure 2.4.55: Simulated and measur
Page 185 and 186:
Figure 2.4.59: Turbidity at NT1 in
Page 187 and 188:
PART 3: DISCUSSION167
Page 189 and 190:
IntroductionIn the previous parts,
Page 191 and 192:
Figure 3.1.1: Average chlorophyll-a
Page 193 and 194:
In conclusion, with high nutrient l
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Dissolved oxygen (g O 2 /m 2 /d) NH
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- DO balanceFigure 3.1.9: Dissolved
Page 199 and 200:
- NH 4 balanceFigure 3.1.11: NH 4 b
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Figure 3.1.14: NH 4 balance in summ
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Figure 3.1.15: Exponential relation
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2. Investigations toward restoratio
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Figure 3.2.3: Simulation based on d
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The distance of recovery is hardly
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upstream inflow. It also implies th
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So far, the wastewater of the Hanoi
Page 215 and 216:
The simulation results of two varia
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Figure 3.2.17: DO at NT2 in differe
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Figure 3.2.21: Evolution of DO at d
Page 221 and 222:
As shown in simulation results, the
Page 223 and 224:
Conclusion and perspectivesConclusi
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processes which were not measured.
Page 227 and 228:
1. Annex 1: Experimental protocols
Page 229 and 230:
PO 4P totalRange Method Standardsol
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- Analytical methods+ BOD: Water sa
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MgClSO 4HCO 3TraceelementsRange Met
Page 235 and 236:
2. Annex 2: Estimation of organic m
Page 237 and 238:
Ratios between heterotrophic bacter
Page 239 and 240:
- To assess the individual local pa
Page 241 and 242:
δmabsj=1n∑n i=1sijParameter rank
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The above definition has a simple i
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4. Annex 4: Mathematical formulas i
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⎛∧ ⎜j = ⎜QC⎜⎝iQ ⎞∂C
Page 249 and 250:
6. Annex 6: Stoichiometric coeffici
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Subs. ValueUnitaerobic sediment exc
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kwind⎛= ⎜⎝ 3.6e1−1 225 10
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DO evolution in Bell Jar experiment
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Firstly of all, NH 4 and DO behave
Page 261 and 262:
Results of Bell Jar experiment at T
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As clearly observed in the figure a
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10. Annex 10: Parameter estimation
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and parameter estimation. It is exp
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First of all, an experimental layou
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ate of phytoplankton also ranks low
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ReferencesAalderink R.H., Klaver N.
Page 275 and 276:
Brown L.C. and Barnwell T.O. (1987)
Page 277 and 278:
Henze M., Grady C.P.L., Gujer W., M
Page 279 and 280:
Liss, P.S. and Slater, P.G. (1974)
Page 281 and 282:
Prieur N. (2001) Dynamique des cont
Page 283 and 284:
Smith, V. H., Tilman G. D., and Nek
Page 285:
Zonneveld C. (1998) A cell-based mo
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